Several years ago I was contracting for about a year at a small-ish company (50 to 60 people). I was surprised to see no internet filtering in place - at all. Nowt. Completely unfettered access to the Net and all its perversions.
I asked the MD why and he just said...."you'll see." Well over the course of the year I was asked to bring logs to the MD about individual internet usage. Each time I was asked for the report the same person was sacked the same day.
He just used it as a way to get rid of staff so had no interest in filtering their access. Of course he only minded what the crap staff were up to. The good ones could watch donkey p0rn for all he cared.